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H. MGLAREN. DEVICE FOR REDUGING THE' PRES-SURE 0F LIQUIDS. No. 393,021. Patented Nov. 2.0. 1888.

(No Model.)

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UNITED Srnrns PATENT Ottica;

HENRY MCLAREN, OF LEEDS, COUNTY OF YORK, ENGLAND.

DEVICE FOR REDUCING THE PRESSURE OF LIQUIDS.

SPECIFICATION forming part of Letters Patent N o. 393,021, dated November 20, 1888.

Application filed January l0.l 1888. Serial No. 260,334. (No model.)

.To @ZZ whom it may concern.- Beit known that I, HENRY McLAREN,a sub- ]ect of the Queen of Great Britain, and a resi-l dent of Leeds, in the county of York, England, haveinvented certain new and useful Improvements in Devices for Reducing the Pressure of Liquids, of which the following isa specification. My invention relates to that class of devices 1n which a valve is counterbalanced, so as to regulate the passage of steam or other fluid from a high-pressure pipe or chamber to anotherpipe or chamber in which the duid should be retained or discharged at a lower pressure; and my invention consists of a device having the parts constructed and arranged to operate as fully set forth hereinafter and as illustrated in the accompanying drawings, in which- Figure lisa longitudinalsectional elevation of a pressure-reducing device embodying my invention; Fig. 2, a transverse sectional elevation.

The casing A of the device, as shown, consists of a rectangular sealed box, 20, with a tubular branch, 2l,at one end having a reduced terminal inlet-port, a, with a surrounding seat for a valve, Q. The opposite end of the box is closed by a detachable head, 22, with ahollow tubular extension, 23, and a packing-box, 24, in which latter turns ascrew-rod, 25, provided with an operating hand-wheel, 26. From the lower side of the box extend two hollow branches, d10, the former with a bore or socket receiving a sliding plug or piston, 3, and the latter with a dischargeopening to receive a plug or piston-valve, C, controlling the flow from the casing to the discharge branch d through the outlet-port b and byway-passage- 12. lhe upper end of the stems of the piston and valve slide in bearings in screw-plugs 3l 32, tting threaded openingsin the top of the box, and each stein is slotted for the passage of a lever pivoted to the pistou-stem aud having a sliding bearing on the valvestem and upon an intermediate fulcrum, la. The fulcrum k is preferably movable to vary the leverage, and, as shown, is a projection upon a sliding bar formed at one end into the valve Q vand with a threaded socket at the other to receive the threaded end of the rod 25, feathers 33 extendingjintolongitudinal slots in the bar and preventing the turning of the bar. By turning the screw-rod 25 the bar 7 can be moved back and forth and the fulcrum brought to any desired position in respect te the lever B, the

valve Q, as the bar 7 is drawn back to alter the leverage,being opened to admit the steam or other fluid under full pressure.

The plugs or piston and valve r3"'(3 are of the same area, and consequently the pressure on both is the same, and when the fulcrum 7c is midway between the bearings of the plugstems 'the two will be exactly counterbalanced and they are inl equipoise; but on the movement of the fulcrum thev equilibrium is disturbed, and although the pressure on each is the same the one farthest from the fulcrum has the advantage of increased leverage over the other, which latter therefore rises under the superior power exerted by the former, which descends.

When the valve Q is opened to admit the fluid to the casing, the fulcrum 7c moves to the left and the valve 3 has then the greatest leverage and will descend until the byport 12 is more or less opened and a part of the Huid escapes to the discharge, the descent of the plug or valve 3 closing a channel, l5, leading from the brauch d to the branch Al0. The pressure in the pipes or chambers with which the device communicates through the branch d acts of course upon the lower side of the plug 3, and as soon as it accumulates sufficiently to balance the difference in the leverage the equilibrium will be restored and the two plugs will take the position shown in Fig. l, closing the communication through the port b.

Supposing the area of the plugs to be one square inch and the distance of their bearings to be two inches, with a fluid-pressure of one hundred pounds in the casing, and the fulcrum to be exactly in the center, the two plugs will be in equilibrium; but supposing the fulcrum to be moved half an inch to the left, the equilibrium will be disturbed andthe plug or valve 3 will at once be depressed and the piston C will be raised until when the pressure beyond .and below the valve 3 rises to sixty-six and two thirds pounds, being two thirds the prressure in the casing, it will counteract the effects of the excess of leveragein favor of the valve-plug 3, and the equilibrium will ICO be restored, the valve will rise, the piston descend, and the port b will be closed. Upon any decrease of pressure below the valve 3, from condensation or otherwise, the preponderance of pressure will be above the valve and will force down the same and open the port b, so as to admit additional fluid below the valve and restore the equilibrium. By this means any desired variation of pressure may be maintained upon the opposite. sides of the Valve 3. By moving the fulcrum 7a the relative )ressurcs above and below the valve 3 may be aried at will, and this adjustment can be effected from without the case without the necessity of `opening the latter.

When it is desired to release the pressure from the outlet-opening or the receiver, it is only necessary to move the fulcrum in the direction to close the inlet-valve Q,when the piston or waste-plug C not only obtains the advantage of a leverage over the outlet-valve, but is further assisted by the pressure already on the under side of the outlet-valve. The waste-plug or piston is then instantly depressed and the outlet-valve raised until it opens the exhaust-passage 15, which opens up a communication between the outlet-pipe or the receiver with which it is connected and the exhaust-pipe by which the fluid escapes and the pressure in the outlet is relieved.

When the valve Q for inlet of iuid to the casing is on its seat and the device is at rest, the fulcrum 7c may be a little nearer the valve 3 of the outlet,so that any pressure which may be in the casing or in the outlet serves to depress the plug of the discharge and tends to prevent any leakage from the casing in the event of the inlet-valve to the same not being properly seated.

I do not here claim any of the features shown and claimed in4 my application for Letters Patent, Serial No. 260,333.

Vithout limiting myself to the precise construction and arrangement of parts shown, l claimM 1. The combination, in a device for redlicing pressure, of a sealed casing having an inlet and sockets for two reciprocating plugs,one constituting a piston, the other a reducingvalve, and a lever, connecting the stems of the plugs and resting on an adj ustablc fulcrum, substantially as described.

2. The casing A, having an inlet-port, outlet-port, and discharge branch, socket receiving a movable plug or piston, and bychannel connecting with the discharge-opening,in combination with a valve adapted to the dischargeopening, connected with a lever also connected with said piston, and a movable fulcrum for said lever, substantially as described.

3. The 4sealed casing, with its inlet-portan'd discharge branch and waste branch and passages 12 15, in combination with the piston and valve-plugs, connecting-lever, and movable fulcrum, substantially as described.

4. The combination of the sealed casing, inlet and discharge ports, piston, and reducingvalve, lever connecting the said valve and piston, and a bar carrying the fulerum of the piston and formed into a valve adapted to the inlet-port, substantially as described.

5. The combination, with the piston and reducing-valve and connecting-lever arranged in a sealed casing, of a movable bar, 7, carrying the fulcrum of the lever, and socket to receive a screw-spindle turning in a bearing in the casing, substantially as set forth.

In testimony whereof Ihave signed my name to this specification in the presence of two subscribing witnesses.

HENRY MCLAREN.

Vitncsses:

HENRY S. LnN'rv, RAPHAEL GAUDIN, Clerks to T. 6L' II. Greenwood Tarde, Solicilors ami' Notaries Public, Leeds, Eng/16ml. 

